This invention relates to a process for the agglomeration of potato granules and to the agglomerates obtained by this process.
Traditional instant dehydrated potato purees are generally produced either in the form of flakes or in the form of granules. The traditional flakes obtained by roller drying of a cooked potato puree have an apparent density of approximately 0.25-0.30 g/cm.sup. 3 and may be reconstituted, i.e., rehydrated with hot or cold water but not with boiling water. The traditional granules obtained by a process in which cut cooked potatoes are disintegrated and partially dried by mixing with recycled dried granules, then finally dried with moderately hot air have an apparent density of approximately 0.9 g/cm.sup. 3 and may be reconstituted with boiling water, but not conveniently with cold water.
The traditional commercial flakes are particularly intended for housewives who may reconstitute them by preparing the exact quantity of hot liquid required and incorporating the flakes therein while stirring gently, for example with a wooden spatula. The granules are particularly intended for catering, their reconstitution permitting the use of boiling water and vigorous stirring, for example with a beater or mixer.
In one known process, potato granules are agglomerated in a rotary drum using a liquid containing up to 10% by weight of milk solids to form 0.3-1.7 mm diameter agglomerates having an apparent density of 0.56 g/cm.sup.3 and each formed by approximately 3 to 20 granules. The object of this known process is to provide a product which can be reconstituted in hot or boiling water while stirring by hand.
In another known process, agglomerates of potato granules smaller than about 0.6 mm in diameter and having an apparent density of 0.4-0.5 g/cm.sup.3 are aggregated using a liquid containing 2.5-10% by weight milk solids to form aggregates larger than about 2.4 mm in diameter and having an apparent density of approximately 0.25-0.33 g/cm.sup.3. The object of this known process is also to provide a product which may be reconstituted in hot or boiling water while stirring by hand, but which additionally has an apparent density comparable with that of potato flakes, such a density apparently being impossible to obtain by a simple agglomeration process without resulting in excessive fragility of the agglomerates.
In another known process, a moist mixture of 75% potato flakes and 25% potato granules is prepared, mixed, left standing, remixed and dried to form porous spheres having a diameter of approximately 0.2-0.8 mm and an apparent density of approximately 0.56-0.64 g/cm.sup. 3 The object of this other known process is to provide a product based on potato flakes which retains the advantages of flakes without any of their disadvantages and which, in particular, may be reconstituted both with cold water and with boiling water while stirring, for example with a mixer.
Finally, there is another known process for the production of flakes reconstitutable in water, in which watersoluble proteins and, optionally, emulsifiers are added to a potato puree before it is dried on a cylinder.